Oil/water separators are known which separate oil and other lightweight pollutants from water. Many such devices are used to purify contaminated water used in industrial processes before returning the water to the environment. Many other devices are used to clean up ground and surface water which becomes contaminated as a result of spillage. Some of the above-mentioned devices employ plural tanks as is shown in U.S. Pat. Nos. 4,252,649 and 3,303,932. Others employ corrugated baffle plates as shown in U.S. Pat. Nos. 2,214,248 and 4,042,512. Such devices, however, typically employ large tanks which have insufficient surface area to operate efficiently.